Figure 3.

3β-HSD inhibition impacts M. leprae intracellular survival. (A, B) ST88-14 SCs were infected (MOI 5:1) for 24 h at 33°C with M. leprae pre-treated for 6 h with vehicle (2% DMSO) or 100 µM compound 1. (A) M. leprae intracellular viability was determined by qRT-PCR. (*p < 0.05 - by Mann-Whitney test)(n=5) (B) SC viability was measured by MTT assay (n=3). (C, D) M. leprae was incubated in axenic medium with 100 µM compound 1, 1µCi/mL of [26-¹⁴C]cholesterol and 1µCi/mL of [1-¹⁴C]palmitic acid for 6 h at 30°C followed by centrifugation and wash and removal of compound 1 (wash off, +) or replacement with fresh medium containing compound 1 (wash off, -), and incubation for 24 h at 33°C. (C) M. leprae viability was measured by radiorespirometry (n=1). (D) Radiolabeled lipids were resolved by TLC with chloroform-methanol 95:5 (v/v) as mobile phase and observed with a PhosphorImager. The graph indicates corresponding densitometry of cholestenone bands (n=1).